Electric connectors



y 28, 1968 w. cHANbLER 3,386,072

ELECTRIC CONNECTORS Filed NOV. 24, 1965 United States Patent 3,386,072 ELECTRIC CONNECTORS Walter Chandler, Theyd'on Bois, England, assignor to The Plessey Company Limited, Ilford, England, a British company Filed Nov. 24, 1965, Ser. No. 509,513 Claims priority, application Great Britain, Nov. 30, 1964, 48,502/ 64 4 Claims. (Cl. 339-194) ABSTRACT OF THE DISCLOSURE In a subminiature multi-pin connector in which enlarged parts of the contact are retained between two abutting body portions, each pin and socket contact has deposited thereon an insulating coating which extends across the butting surfaces and thus prevents electrical creepage between the contacts along the butting surfaces.

This invention relates to electric connectors incorporating plugs and/or sockets and is especially but not exclusively, applicable to subminiature multi-pin plug and socket connectors having small spacings between adjacent pins and sockets.

In miniature multi-pin plug and socket connectors in which the pins and sockets are located in very close proximity in each connector member, it is desirable for the pins and sockets to be removable from the connector body parts to enable electrical connections to be made to them, as for example by soldering or by crimping wires to the pins and sockets. In my co-pending patent application Ser. No. 338,257 (Patent No. 3,259,871) I have described a plug and socket connector assembly in which the wired pin and socket contacts are held captive within the respective plug and socket connector bodies by arranging that each of the bodies is made in two co-acting parts which when applied together clamp enlarged portions of the pin and socket contacts between opposed faces of the two body parts, and wherein, to prevent short electrical creepage paths between the enlarged portions of the pin or socket contacts across said opposed faces of the body parts which constitute sources of electrical weakness, a resilient or flexible insulating sleeve is provided which circumferentially surrounds the enlarged portion of each pin or socket and extends longitudinally in both directions from the butting surface. With this construction considerable diificulties arise when the dimensions become very small (i.e. subminiature connectors). The insulating sleeve then becomes unmanageably small and the comparatively large minimum wall thickness of the sleeves prevents the desired subminiature dimensions from being obtained.

It is an object of the present invention to provide a subminiature connector in which this limitation is overcome.

According to the invention the pin or socket contacts are coated with an insulating material. The insulative coating while preventing the formation of short electrical creepage paths, which in subminiaturization is a particularly serious problem, avoids the limitation as to minimum thickness to which insulating sleeves are subject, and thus allows the subminiature dimensions to be easily achieved.

The insulating coating may be an enamel coating and can be applied in any convenient manner as part of the manufacturing process of the subminiature pin or socket contacts.

Thus it will be appreciated that the pre-insulated contacts of the present invention retain many advantages of Patented May 28, 1968 'ice the contacts provided with an insulating sleeve described in the above-mentioned co-pending application and also provide reduced manufacturing costs as well as eliminating the handling of prefabricated sleeves.

Preferably all of said connector members are provided with such an insulating coating, and in one embodiment the insulating coating on the or each connector contact is extended beyond an end of the housing in order to increase the electrical creepage path between adjacent contacts.

In applying the invention to a multi-pin plug and socket connector in which each pin or socket contact is provided with an enlarged portion and in which the housing is formed in two parts which are adapted to clamp said enlarged portions therebetween, the insulating coating is provided on each connector contact at least in the region of said enlarged portion so as to reduce the possibility of electrical leakage across the opposed faces of the housing parts.

In order that the invention may be clearly understood and readily carried into effect it will now be more fully described with reference to the drawing accompanying the specification in which; FIG. 1 shows a longitudinal sectional view of an electrical multi-pin plug and socket connector member according to the invention, and; FIG. 2 shows a longitudinal sectional view of an electrical multipin socket connector member according to the invention.

Referring now first to FIG. 1, the plug member of the connector comprises conducting connector contacts in the form of plug pins 1 integral with larger diameter portions 2 having further enlarged portions 3 as shown. Conducting connections are made to the pins 1 by inserting and crimping the bared ends 4 of insulating conductors 5 in terminal recesses 6 provided in the ends of the larger diameter portions 2 remote from the pins 1. The plug part of the connector also comprises a housing having two co-acting parts 7 and 3 which are clamped or otherwise secured together by means not shown so as to clamp the enlarged portions 3 of the connector members between opposed end surfaces 9 of the housing parts 7 and 8. The larger diameter portions 2 of the connector contacts have a coating 10 of electrically insulating material, such as of a suitable plastics material, for example polyvinyl chloride (P.V.C.) or enamel, applied to them. In the particular embodiment illustrated the coating 10 is applied over the whole of the exterior surface of the larger diameter portion 2 of each connector contact, but if desired said coating 10 can be confined to the vicinity of the enlarged portions 3, i.e. in the region of the opposed end surfaces 9 of the two body parts 7 and 8. The provision of the coatings 10 between adjacent connector contacts in the region of these opposed end surfaces reduces electrical weakness compared with a construction in which the insulating coating is not provided. In the particular embodiment illustrated by FIG. 1 the insulating coatings 10 are provided along the entire length of the larger diameter portions 2 of the connector contacts in order to increase the lengths of electrical creepage paths between adjacent contacts. Moreover the arrangement is such that the end of the larger diameter portion 2 adjacent the pin 1 of each connector contacts is set back from the corresponding end of the housing part 7 so as to increase the electrical creepage path around said end of the housing part 7. In the embodiment illustrated the ends of the larger diameter portions 2 remote from the pins I extend beyond the housing part 8, although, if desired they may be set back from the end of the housing part 8.

Referring now to FIG. 2, the socket member of the connector is similar to the plug member as will be evident from the drawing except that instead of having pins each integral with a larger diameter portion, the socket connector contacts 11 are predominantly of the same outside diameter throughout their length having at one end a recess 13 forming a socket and the other end a recess 14- for securing a conductor 15 to the connector contact 11. An enlarged portion of each contact 11 is clamped between opposed end surfaces of two housing parts as in the case of the plug member of the connector. In the embodiment shown the whole of the exterior surface of each socket contact 11 is provided with an insulating coating 12 which may be of the same or a different electrically insulating material to the coating 10. In the case of the socket contact 11 both ends of each contact are set back from the corresponding ends of the housing parts 16 and 17.

The housing parts of both pin and socket connector members will usually be made of electrically insulating material, but the construction shown in the drawing enables the housing parts to be made of electrically conducting material, if desired, by virtue of the fact that the contacts of each of the plug and socket member of the connector are electrically isolated from one another by the insulating coatings 10, 12.

Although the invention has been described with particular reference to one embodiment thereof, it may be applied to other forms of electric connectors which comprise a plurality of contacts which are required to be insulated from one another.

What I claim is:

1. An electrical plug-in connector member comprising in combination at least one contact, two body members secured to each other so as to face each other on a surface transverse to the plug-in direction, said body members having for each contact aligned through bores extending in the plug-in direction, and jointly constituting a contact-accommodation chamber having a widened portion at the said surface, each contact including a shaft portion accommodated in such chamber and having a shoulder-forming flange accommodated, and clamped in the axial direction of the through bore between said body members, in said widened portion of the chamber, said at least one contact having deposited thereon an insulating coating which extends across the said surfaces and transmits the clamping force.

2. An electric connector according to claim 1 in which said insulating coating is provided on the whole of the exterior surface of said at least one contact which is engaged by said body members.

3. An electric connector according to claim 2 wherein an end portion of said at least one connector contact extends beyond said body members, and is covered by said insulating coating,

4. An electric connector according to claim 2 comprising a portion of said housing extending beyond an end of said at least one contact.

References Cited UNITED STATES PATENTS 2,883,308 4/1959 Yamada. 3,158,424 11/1964 Bowen 339l76 X 3,242,456 3/1966 Duncan 339--176 X 3,259,871 7/1966 Chandler 339196 X MARVIN A. CHAMPION, Primary Examiner. JOHN R. MOSES, Assistant Examiner. 

